Finding the empirical formula would be extremely helpful in an identifiying an unknown compound. If you had the empirical formula, you have half the battle because all you know what elements the compound is composed of and the relatve amounts of each. If you know the molecular weight(which is actually quite easy to find) and the empirical formula then you know the molecular formula. In simple cases, there will be only one possible structure for a given molecular formula. In other cases there will be many possible structures, which means you need other methods - you cover this when you take organic chemistry, which done in the second year of college.